Fire control apparatus



Nov. 3, i953 H. c. FORD RIRE CONTROL APPARATUS.

5 Sheets-Sheet 2 Filed July 26 11V VEN TOR lfm/m72@ LA C. For@ TT ORNE YS Nov. 3, i953 H. c. FORD 2,657,464

FIRE CONTROL APPARATUS Filed July 26, 1928 5 Sheets-Sheet 3 434 MM 44m A TT ORNE YS n Fatenteci5 Nov. 3, i953 2,657,464 FIRE CONTROL APPARATUS Hannibal C. Ford, Jamaica, N. Y., assignor to The Sperry Corporation, a corporation of Dela- Ware Application July 26, i928, Serial No. 295,437

(Cl. {i3-49) S2 Claims.

This invention relates to apparatus for controlling the fire of ordnance and while especially intended for controlling ordnance used against aerial targets may be employed for ordnance used against surface targets.

It is an object of the invention to provide re control apparatus or determininggthecpurseand Speed cfa ters-et, andinthe Casse? en ,aerial target itsl rateof climb, for use in predicting future positions of the targetin order that the controlled guns may be properly aimed for their projectiles to nit the target.

It is a further object of the invention to provide an apparatus which when properly1 adjusted will automatically maintain the line of sight to a target in train and elevation and automatically maintain the range, thereby relieving the operators oi the apparatus ol` the necessity ci continuously performing the operation or" following the target in train and elevation and putting in the range except insofar as they may be required to make adjustments 'fro'.i time to time to the automatically maintained values to correct for changes in the motion of the target.

While in its simplest form the invention is embodied in a single instrument having a sighting element and a computing mechanism in proximity and operatively related to each other, the invention also contemplates the physical separation of the element and the mechanism With suitable operating connections between them.

The invention further contemplates the automatic maintaining of the line ci sight of another device, such as a similar standby instrument or a range iinder, upon the saine target as the controlling instrument in order that the standby instrument may be in condition to take control instantly or insure that the range finder operator is observing the same target as theobserver at the controlling instrument.

The particular nature of the invention as .vcll as other objects and advantages thereof will appear most clearly from description of preferred embodiments as shown in the accompanying drawings in which Figs. lo!Y and` lb constitute a diagrammatic perspective view of a form of instrument in which the sighting element and the computing mechanism are arranged in proximity,

Fig. 2 is a wiring diagram of the instrument of Figs. la and lb,

Fig. 3 is an enlarged perspective View of certain elements of the computing mechanism to show them more clearly than does Fig. la,

Fig. 4 is a similar view of a part of the switching mechanism o1 Fig. 2,

Fig. 5 is a quadrant diagram,

Fig. 6 is a diagrammatic View of a modied form of the invention adapted to be used with the computing mechanism of Figs. la and 1b most of which has been omitted for the sake of simplicity, and

Fig. 7 shows on an enlarged scale a part of the range finder of Fig. 6.

Referring particularly to Figs. la and lb it will be understood that all the parts while shown diagrammatically therein are in practice mounted upon amember l rotatably mounted upon a pedestal 2 within an annular rack 3 fixed to the top oi-the pedestal. Two standards ii and 5 extend upwardly from the member l and between the tops of the standards are mounted two telescopes S and "i for the pointer and trainer respectively, these telescopes being connected by a rod 8 so that they move together in elevation as well as in train.v Mounted in a depending portion 9 of the standard is a trainers hand- Wheel iii provided with a bevel gear il which. meshes with a bevel gear l2 connected to the side i3 of a diierential i3. The center l of the diierential is connected to a shaft t4 which extends through a bearing I5 forming part of the standard l and carries at its lower end a pinion l5 meshing with the training rack 3. The second side 13" of the differential is connected by a pair of bevel gears Il to a shaft I8 mounted in a bearing i9 on the standard t. Through gears 20 the shaft is connected to the center 2l of a differential 2i. One side 2l" of the differential is connected through gears 22 to a repeater motor 23 actuated from a suitable direction indicating instrument, such as the gyrocompass of the ship on which the apparatus is mounted. The other side 24' of the differential is connected through gears 2d to the roller 25 of a variable speed device 2S of the type shown in my Patent No. l,3ll,!5 of October 7, 1919. Briey this device consists of a disc 2l driven at uniform speed by a motor 28 and a ball carriage Z9 betweenA the disc and the roller and adjustable from other elements of the mechanism as will be hereinafter described.

The shaft ift to which the center of the differential I3 is connected extends upwardly into a bearing 25 at the top of the standard l where it is connected by a pair of bevel gears 3U to a shaft 3l which through gears 32 turns a dial 33 to give indications of target bearing referred to a fixed line, which, when the instrument is mounted on board ship. is usually the center line of th ship. the shut El is inovcd accori-ance i h thetraining movement of the inc y inient as the target is followed by the trainer -rho observes it through the telescope This bearing v-Jill be hereinafter referred to as rela-` tive target bearing.

The shaft 3! is continued into the computing mechanism of the instriunent where it is connected by a nail' of bevel :ears 34 to a shaft 35 which extends into the portion of the instrument shown in Fig. 1b. it its lower end the shaft is connected by bevel gears 35 to a shaft 37 which carries a pinion 3S engafrinsr a rear 39 which is therefore turned in accordance with relative target bearing. The shaft 3'! carries a. second pinion 43 which engages a gear 4! also turnable in accordance with relative tarflet bearing. The gear d! is provided with posts 42 carrying an Own Ship dial Q3 bearing,r a representation of a shin and readable against a pointer 44 to show the bearingr of the target with respect to the fore and aft line of the ship.

Near its upper end, the shaft 35. see Fig. 1 is connected by bevel gears 5 to a shaft 4t vfhic is attachee to the center lll of a differential l One side 4? of the differential is connected gears E13 to a shaft El which extends throueh the. instrument to one of the gears 22 so that this is driven in accordance with the course of the shin since it is rotated from the motor 23 actuated from the gyro compass of the shin.

The other side 41" of the diiierential is connested by bevel gears to a shaft 5l which is connected by bevel gears 52 to a shaft 53 which extends into the portion of the instrument shown in Flic. 1b there throueh bevel it .is connected to a shaft 55. The lower end of shaft carries :i bevel gear 5B meshing with a aear 5l' attached to one side 58 of a diiferential 5 8. the remaining elements of which will be hereinafter described. The bevel gear 5'? meshes with a aear 59 on a shaft Gil which through bevel gears is connected to shaft 52 carrying a pinion E3 which meshes with n ringr S4. surroundina the. Own Ship dial G3.

llince the shaft 35 and therefore the center 4?' of differential. Il?, see Fig. lo. are driven in accordance with the relative bearing of the target and the shaft lie and therefore the side ill of the differential are driven in accordance with the course of the shin, the other side M" will be turned in accordance with the algebraic sum of these two rmantities which reloresents the true be ic of the target. that is the target bearinf referred to the meridian. Through Aeears 5f), shaft 5i and gears 52, the shaft 53 will be driven in accordance with the true hear-ina of the target ani through gears 55,. shaft 55. gears 55. 5'! and 59. shaft s El, shaft B2 and ninion 63 will turn the rma 6c so that its graduations read aaainst the pointer 4d will show the true 'bearincJr of the tar'zet. Since the dial 63 is turned in accordance with the relative bearing of the target. the rin'r 55 when read against the Zero mark of the dial will show the course of the ship since the course is the algebraic difference between the true bearing of the tarlet and its relative bearin other Words, the mechanism just de- .c ibed ind catas the relation of the fore and aft ine of the shin to the meridian by elements movble in accordance with the true and relative hearings of the target.

The shaft 53 is provided at an intermediate point as shown in Fig. la-With a pinion 65 which meshes with an annular gear 66 provided with a pair of posts 67 to the other ends of which is attached a ring 68 turnable in acc rdance with ihc true bearing of the target as is the ring 34 shown in Fig. 1b. In other words, these ri are correspondingly actuated from thc shaft z in accordance with the true bearing of the target but the ring 58 reads against the pointer S9 displaced relatively to the ring through 185* from the pointer M against which the ring E54 is readable.

The 'pinion 65 also inf-hes with a pinion forniing a part of one side IG of a dierential l.. The center l0 of the differential is connected to a shaft l! which extends into the portion the instrument shown in Fic. lb. Slide mounted on the end of the shaft is'. a clutch adapted to be operated by an arm 73 nivoted nl and provided with a handle l5. The clutch is provided with a pinion 7G adapted when in the position shown in l?) to engage, a gear 'il to which is attached a handle 15 adapted to be operated in accordance with the estimated coursel of the target with respect to the. meridian, which is the same reference lino from which thc true bearina of the tar-get is measured. The clutch l2 also carries a bevel gear 'i9 adapted when thc clutch is shifted inv-Jardly alongr the shaft Il to engage a bevel gear 8G on the end of a shaft 3l which by means of bevel gears 32 is connected to a target course motor 83 forming part of the automat-ic rate control feature of the instrument which will be described hereinafter- Referringr to la the second side lll of the diierential le is provided with a pinion 84 w lich meshes with a gear 85 provided with posts l' carrying a target dial 81 mounted Within the rind. 58 and carrying a representation of an aircraft target. The target dial reads against the pointer SS to indicate the course of the target with resoc to the line of sia-ht or terne angle as it sul hereinafter be called for simnlicity. The tarzc'r. dial alsorcads ncainst the graduntions of thc ring,r 5B to indicato the course of the target. with reference to the meridian. that is. the true cou-:se of the target.

Assuming that the shaft l! is set hv the oreal: 'i8 through `pinions 77 and l5 and clutch i2 in accordance with the estimated course of the target. a corresconding setting of the center '50" of the differential 'le will be made. Since as already described the side G' of the differential is turned by the shaft 53 in accordance with the true bearing of the target and the center lll is turned in accordance with the estimated course of the target the resultant movement of the third side 70" will be in accordance with the algebraic sum of these cuantities, that is, the target anale. The movement of the side will be imparte: to the gear 35 and the target dial. 8l connected thereto so that the latter reads against its index or pointer 69 and will give the tarqet angle,

The side 15"' of differential 'le is orovidcd with an extension 88 having a :ear 89 mcshint7 with a gear 98 which will therefore he turned in accordance with the target angle as e ar 85 and target dial 81. Gear 9c is provided i. ch a slot 9i within which is mounted n, slidable block 92 carrying,r a rod S3, the forward end of which extends into a spiral groove 9d in a target sneed gear 95.

The target speed. gear 95 meshes with a gear forming part of the side 9G of a differential 85. The target anale gear 99 meshes with a gear 9.' on a shaft 9S attached to the center 96" of the differential S5. The gear El drives through a gear 39, a quadrant switch iGS which will be described in detail hereinafter. The other side 95"' of the differential is provided with a gear which meshes with a gear on a shaft 52 which extends into the part of the instrument shown in Fig. lb Where through bevel gears I, shaft |94 and bevel gears SSE, it drives shaft Hl. Slidably mounted on the end of the last named shaft is a clutch |67 like the one previously described and designated 72. The clutch is?? is shifted on the shaft |86 by an arm e8 provided with an operating handle |59. The clutch carries a pinion io adapted when in the position shown in Fig. 1b to engage a gear i I to which is attached a handle I I2 adapted to be operated in accordance with the estimated air speed of the target. The clutch also carries a bevel gear IIB adapted when the clutch is shifted inwardly along the shaft |08 to engage a bevel gear i lli on the end of a shaft l i5 which by means of bevel. gears I l is connected to a target speed motor I I7 forming part of the automatic rate control feature of the instrument. As shown in lc the shaft IGZ drives through gears |92 a dial |62" for showing the air speed of the target put into the instrument.

In the operation of the parts described just above and regarding the shaft |32 as fixed, the side B" of differential S5 will also be fixed since it is connected to the shaft |82. Therefore the movement imparted to the target angle gear S9 by the differential 'lS will through gear 97, shaft 93, center 95 and side 855' of the differential 96 turn the target speed gear 95 in unison with the target angle gear 9B.

When, however, shaft 5&2 turned in accordance with the estimated air speed of the target from the handle I2 through gear I I i, pinion i I @3, clutch |92', shaft |95, gears |05. shaft HM and gears W3, the gear lill will turn the side 95 of the differential. Regarding the center 95 as fixed since itis connected to the target angle gear SS, side 96 will be turned to shift the position of the target speed gear 95 with respect to the target angle gear. As the target speed gear turns, the rod SS which fits into the groove S43 will be shifted to alter the position of the block 92 in the slot 9| of the target angle gear SQ.

The pin e3 extends on the other side of the bloei: S2 into intersecting slots of a pair of recgear The arrangement is such that the horii zontally movable slide I3 is positioned in accordance with the horizontal lateral deflection of the target due to its own movement, that is, the horizontal component of the air speed of the target perpendicular to the line of sight. This component is equal to the product of horizontal range of the target RH and the rate of change of bearing dBi", or RndBT due to the target.

The vertical movable slide IIS is positioned in accordance with the rate of change of the horizontal range of the target due to its air speed, or more briefly, the horizontal range rate of the target, designated CZRH.

The slide I I8 is provided with a rack which meshes with a pinion on a shaft |2| which through bevel gears |22 is connected to one side |23' of a differential |23, the remaining elements of which will be hereinafter described.

In a similar manner the slide IIS is provided with a rack which meshes with a pinion I 24 on a :In u,

D shaft |25 which through bevel gears |26 is connected to the side |27 of a differential |21, the remaining elements of which will also be hereinafter described.

Referring to the left hand portion of Fig. lb, the shaft 3| carries at its lower end a bevel gear |28 which meshes with a corresponding gear i253 on a clutch |30, similar to clutches I2 and 'l, slidably mounted on the end of a. shaft |3| and adapted to be shifted by the arm 'I3 and operating .handle 15. The clutch carries a pinion |32 adapted to engage a gear |33 provided with a handle |34 adapted to be operated in accordance with the estimated direction of the wind. The purpose of connecting the clutches 'l2 and |39 to the arm `I3 as shown in Fig. 1b is to prevent the motor 83 from simultaneously driving both shafts and IBI as will appear more clearly in connection with the description of the rate control features of the invention. The gears l? and |33 are elongated so that when the arm 'i3 occupies a position parallel to shaft 8| the pinions 'E5 and I 32 will be in engagement with their corresponding gears so that target course and wind direction may be simultaneously put into the instrument by manipulation of handles 'iS and |34 respectively. When the arm 'I3 occupies the position shown, target course may be put into the instrument by turning handle 1B, but the shaft ISI is disconnected from the wind direction handle |34 and connected to the motor S3 through the clutch |35, gears |29 and |28 and shaft iiI. larly, when the arm 'I3 is shifted to bring the gears 'i9 and S0 into engagement, the shaft 'II is disconnected from the target course handle 'i3 and connected to the motor 33, while the shaft |3| isconnected to the wind direction handle l 34 through the clutch |323.

The shaft I3! is connected to the center 53" of differential 58. The other side 53 of this diferential is provided with an extension |35 carrying pinion |35 meshing with a wind angle gear |31 provided with a slot |38 within which is mounted a slidahle block |38 provided with a rod |43, the forward end of which extends into a grooveJ lliI in a wind velocity gear |532. angle gear |32l meshes with a gear M3 on a shaft ldd attached to the center of a differential |155. One side of the differential carries a pinion |415 meshing with the wind velocit-y gear M2. The other side i' of the differential is connected through bevel gears |151 to a shaft |33 which through bevel gears It is connected to a shaft |59 on which is slidably mounted a clutch |5| similar to the clutches previously described. This clutch is shiftabie upon the shaft i by the arm |98 and handle ld, t carries a bevel gear |52 adapted to engage a corresponding gear 53 on the lower end of shaft I5 to which the motor I I? is connected through gears i I5, the arrangement being such that the motor cannot he simultaneously connected to shafts it and |59 through clutches |91 and Ii respectively. In otherwords, this arrangement is like that previously described in connection with target course and wind direction.

Clutch |5| is provided with a pinion |54 adapted when the clutch is in its forward position to mesh with a gear i 55 having a handle 156 adapted to be operated in accordance with wind velocity. At the outer end of shaft |59 is a pinion |57 meshing 'with a gear |53 to which is connected a wind velocity dial I 59.

The pinion |36 on the extension |35 of the side 58"' of differential 58 engages a gear |99 which Simi-r The wind through a. shaft and gear train iBl drives a wind quadrant s :itch iZ which like the quadrant ,switch will he hereinafter described in detail. The outer end of the extension 35 is connected by bevel gears ESS to a. shaft H3G which extends into o portion cf the instrument shown in Fig. la where through bevel gears e5, shaft |66 and Acinion |51 it drives an annular gear |53 surrounding the ring E8 and provided with an index |53 readable against the graduations of the ring G3 to show the direction from which the wind is blowing referred to the meridian.

Referring to 1D and assuming that the clutch has been shifted to mesh the pinion |32 with the gear and that the handle i3d is turned in accordance with wind direction, the shaft 13| and therefore the center 5S" of the diierential 538 will he correspondingly turned. Since the side of the differential is driven from shalt in accordance with the true nearing of the target tie other side 58 will be driven in accordance with direction of the wind referred to the line of sighty or wind angle as it will he called hereinafter The movement of the side 58" will he imparted through pinion |36 to the wind angle gear |31 and the wind quadrant switch E The wind-angle ear ring ESB of Fig. la will also ce driven through bevel gears |53. shaft E bevel gears |55, shaft |515 and pinion |61. The index |59 of the wind ring will when read against the true hearing ring G3 show the direction of the wind as set into the instrument bv manipulation of handle. The rotation of wind angle gear 231 will through pinion idf-l and shaft lef drive the center 45' of diierential |45 and regarding the |'H as ined at this time, the other side |135" will he dr n to turn through pinion lfi. the wind velocitd gear 52 in urL'son wi 'th the wind ongle gear |31. When, however, the shaft M8 is turned in accordance with the estimated wind velocitv from the handle |555, assuming the clutch 15| has 'leen shifted to bring its pinion i5?, into engagement with the gear |55, the side Ii'" of the differential will he turned and regarding the center |55 as xed. the other side |65" will be turned to shift the 'wind velocity gear |42 with resoeot to the wind ongle gear |31, Due to the angular movement of gear |31 the slot |38 will be positioned in accordance with the direction of -he wind. while the block |39 and pin |43 will he shifted oy the relative movement of the wind velocity gear |52 with respect to the wind angle gear |31 to position the pin |158 in accordance '-.vith the velocit;Y of the wind and its angle with respect to ne of sight.

The ein Ifi is extended through intersecting slots of o of. rectangular slides |10 and lll, the former of which is moved in accordance with the deflection of the target due to the effect of the vind anon it. that in accordance with the quantity RedBw, where RH is the horizontal range and the rate of change of bearing due to wind. The slide |15 is moved in accordance with the rate of change of the horizontal range of the tarcet due to the effect of the wind, that is in accordance with the quantity dRw. The slide I'i') is provided with a rack portion engaging a pinion l??? on a shaft |13 connect-ed through bevel gears |14 to one side |15 of a differential |15. the remaining elements of which will presentlv be described. Similarly the slide |1| is provided with reel: portion engaging a pinion |15 on a shaft |11 connected by bevel gears |18 to one side |19 of a'diferential |19, the remaining elements of which will also presently be described.

Reference has previously heen made to the gear see Fig. lb. which is turned in accordance With relative target bearing from the training element of the instrument. This gear meshes with a pinion on a. shaft |8| which is connected to the center S2 of a diierential |82. One side |82" of this differential is provided with an extension |83 which by means of a pinion |84 is connected to an Own Ship speed gear |85 provided with a groove |83 within which is fitted one end of a pin |131 passing through a block |88 slidablv mounted in a slot |33 in the gear 3S. The other side of the differential |2 is provided with a gear meshing with a pinion on a shaft having a handle and connected through gears |52 to a dial |3 for indicating the speed of Own Shin when this quantity is put into the instrument by operation of the handle.

As in the case of the wind n.tion and velocity gears hereinheore describe .le Own Ship :need gear v. l. Eizo turned in unison with the gear 3S through the diierential iti when the side i315!" is lived, it will he due to its connections to the ha hen, however, the handle is turned in ith the speed of the shi-o the gear ce shi d with respeci; to ear 39 to position pin i3: in accordance with the sneed ci the The movement of gear 3G ccsition the nin accordance w ith the re c rget hearing.

The pin passes through vth intersecting ci nair of rectangular and |35 the former of which is moved in accordance with the deecton to the movement oi' Own Shin, that is RHdBo, while the latter moved in acrate of chante in range due iconent movement of the sirio toward c from the target, that i" 'f' to. The slide provided with a rack; no on engaging a on a shaft iii? which 'through oen-e1 gears |93 is connected to a sh ,"t attached to the center |15" of dierfntial i Since as prely erolained Lhe s..ie ll' is turned in accordance with the in ection due to the wind, the movement imparted to the other side |?5" will be the algebraic of the tion due to the wind and the del tion clue to movement of Own Ship. e resultant movement of the u van.

hy bevel gears to the side |23 oi' ne differentand thus recei' es a movement in afford/ance with cetion which the resultant horizontal lateral oci', will lee de gnatcrl Red.

Referring to Fig. 1b the vertcai H95 is provided with a rack portion en pinion 2&3 on a si aft E134 connected oy oev 1 gears S35 to a shaft 225 attached to the cen i1 of the differential |19. Since the side of this differential is moved from the slide |1i in accordano with the rate of change of range due to the wind. the other side 2'5" will 'ce moved in accordance with the algebraic surf; of this quantity and the rate of change of range due to the movement of Own Ship. The resultant movement of the side |19H will be transmitted by gears |88' and shaft IBI to the center L27 of the differential i2]r shown in Fig. la. Since the'side |27' of this differential is driven from the slide lle in accordance with the horizontal range rate due to the target, the third side |2`|" will be driven in accordance with the algebraic sum of these quantities and the resultant horizontal range rate due to wind and movement of Own Ship and target, that is, in accordence with dBu. The resultant movement of the third side |2l" will be transmitted through bevel gears 201 and shaft 238 to a gear 'Zet connected to a differential which will be hereinafter described.

The shaft 262 is provided with a pinion 2H! which meshes with a gear forming part of one side 2li' of a differential 2li. ri'he center 2| |I of the diiierential is attached to a shai't 2 i2 carrying at its outer end a cam disc 253 for actuating a contact device 2id to shift an arm 2|5 into engagement with one or the other of a pair o contacts 2 i5 which as shown most clearly in the wiring diagram of Il* 2 control the operation or" a motor 2|? as folio s. The Contact arm 215 is electrically connected to one main tit of a source of current supply. One or" the contacts 'M5 is connected by a conductor 2id to a contact element '12S of a control switch 22| consisting of a bar 22| of insulation and carrying a number of contact elements. From the contact eiement 220 the circuit continuos through another Contact "'72 3 to one field winds., and conductor 2o. ing of the motor 2H and thence through the armature to the other main 221i of the source of current supply. The other contact 2id is ccnnected by a conductor 225 to a contact 22S of the control switch 22| and continues through contact 22?, conductor 23 and a eld winding or" the motor Ell' wound reverseiy to the other winding and thence through the armature to the main 22e.

The direction of rotation of the motor 2H is therefore determined by the direction of rotation imparted to the cam 2| 3 from the shaft and pinion 'i through the side 2li' and center 2H" of diierential 2H. Through a pinion the motor drives a gear 230 on a shaft 23 which aiso carries a pinion 232 meshing with a pinion for ing part of the second side 2||"' of the di rential 2i i This arrangement is such that as the motor 2l? drives the shaft 23| the center 2| i of the differential will be driven from the side 2| i" in a direction, opposite to which it was t fen from the side 2H by the shaft 252 and pinion iii), to actuate the cam disc 213 to break the circuit of motor 2li. These operations occur successively o nc result that the shaft EI is C en in o accordance with the moveaft ad.: and pinion 2| but with increased due to the interposition of the motor 2|?, or in other words, the mechanism constitutes foilow-up system for driving the shaft 23|. At iov/er end the shaft carries a dial 5:""3 which indicates the quantity RHdB or iis en zivalent RdEir.

While the relative knots component of the target across the line of sight is the same in the inclined plane 'as it is in the horizontal plane the direct range R is different in the inclined plane from the horizontal range RH to a point directly under the target. Therefore the angular rate in the inclined plane expressed as dBN diiers from the angular rate in the horizontal plane expressed as dB. Liasmuch as the relative knots component of the target is proportional to angulil lar rate multiplied by the range the knots component in an inclined plane equals RdBN and the knots component of the target in a horizontal plane equals RHdB. Inasrnuch as these knots components are equal to RdBN equals RHdB.

The other end of shaft 23| carries a pinion 234 Which meshes with the rack portion of a slide 35 which will therefore be moved horizontally in accordance with the quantity RdBN. A slotted'bar 235 is attached at its lower end to the slide 235 and at its upper end is supported by a fixed pin 231. is a pin 238 projecting from a member 239 slidably mounted on the horizontal arm of a T- shaped member :258 having at the lower end of its vertical arm a pin 24| which nts within a groove 2&32 in gea-r N3 adapted to be turned in accordance with 'the range of the target through the following connections. A crank 2M adapted to be turned by an operator known as a range setter' is provided on one end of a shaft 265, the other end of which is connected to the center 246 of a differential 24S. One side 24B of this differential is provided with a gear which meshes with a gear 2:21 on a shaft carrying a pinion 24S meshing with the range gear 2:23 and also carrying a range dial 259. Considering at present the third side 25.6" of the differential 255% as being fixed, the movement imparted to the shaft 2de by the crank 24s. will through the center 25S', the side 256 and the gear 2li? drive the shaft 228 and consequently the gear 2&3 in accordance with the direct range of the target. The cam groove 262 on this gear is formed in accordance with the recprocals of the range values so that the vertical movement imparted to the member 24S is in accordance with Therefore the pin 23B will be adjusted vertically in accordance with and horizontally by the movement of the slide 235 in accordance with RdBN thus multiplying these .quantities and giving dBN.

The pin 23e also passes through the slotted vertical arm of a slide 25|, the horizontal arm of which will therefore be moved in accordance with CZBN. A portion of this slide is provided with a rack which meshes with a pinion 252 on a shaft 2 5o to the other end of which is attached a pinion 254- meshing with a rack on slide 255 which will therefore be moved in accordance with dBN.

If the instrument is being employed for controlling the firing of guns against aerial targets, the quantities thus far dealt with will be referred to a line of sight which is elevated with respec to the horizontal at an angle designated A. The sighting instrument, however, is mounted to train in a horizontal plane so that in order to compute the training movement required to maintain it on the target it is necessary to refer the quantity dBN to a horizontal plane. This may be done by dividing it by the cosine of the angle A or multiplying it by the secant of this angle. in the instrument disclosed herein the latter method is employed.

For this purpose there is pivoted to the slide 255 a slotted bar 255, the other end of which is retained by a xed pin 252'. A rod 258 passes through the bar 25S and is attached to a member 259 slidably mounted on a rectangular slide 233.

Fitting Within the bar 236 demnos At the upper end of the vertical arm of this slide is a pin 251 which extends into a groove 252 in a gear 283, the groove being arranged to impart to the pin 251 and slide 260 a vertical movement in accordance with the secant of the angle A when the gear 253 is turned in accordance with this angle.

In order that the gear may be thus turned a pointers handwheel 264 mounted in a depending portion 255 of the standard 5 and carries a bevel gear 255 which meshes with a bevel gear 251 forming part of one side 2GB' of a dinerential 258, the center 288 of which is attached to a shaft 250 extending into a bearing 21% at the top of the standard 5 where by means of a pair of bevel gears 211 it is connected to a shaft 212 extending into the computing mechanism of the instrument. The shaft carries a worm 213 which engages a gear sector 21:1 mounted on the standard 5 and connected by a link 215 to an arm 215 attached to the rod 8 connected between the telescopes 5 and 1. By virtue of this arrangement the telescopes are adjusted vertically by the pointer who observes the target through his telescope f5 while turning his handwheel 224. The shaft 212 is provided with a pinion 211 meshing with a'gear 218 for turning a dial 219 to show the values of the angle A.

At this point it will be explained that the second side 238' of differential 25B is connected by a pair of bevel gears 280 to a shaft 281 connected to the roller 282 of a variable speed device 283 similar to device 25 and consisting of a disc 254 driven at constant speed by the motor 28. Between the disc and roller is a ball carriage 255 adapted to be set by a rack 2355 in accordance with the rate of change of elevation angle, dA, as will hereinafter appear.

The end of shaft 212 within the computing mechanism is connected by a pair of bevel gears 281 to a shaft 288 which carries a pinion 28s` meshing with the secant gear 263 whereby the latter is turned in accordance with the angle A to correspondingly position the slide 25B and the pin 25B vertically. The pin is also positioned horizontally by the slide 255 and arm 255 so that its resultant position represents the product of dBN and secant A to give the rate of change of bearing referred to a horizontal plane, which Will be designated dB.

The forward end of pin 258 extends into the slotted vertical arm of a horizontal slide 28S which is therefore moved in accordance with the quantity dB and through a pinion 2S 1, a shaft 222 and a pinion 293 moves a rack 29, connected to the ball carriage 29 of the variable speed device 25 to position the latter in accordance with the quantity dB. The position of the ball carriage relatively to the center of the constant speed disc 21 determines the speed at which the roller 25 will be driven. The side 21 of differential 21 will be driven through the gears 24 from the roller 25. Regarding the other side 21" as fixed the center 2|' will be driven and through gears 2U the shaft 18 will be driven to drive the side 13' of the differential 13. Regarding the trainers liandwheel 1D as fixed the side 13 of the differential will also be fixed so that its center 13" will be rotated and through the shaft will turn the pinion 15 relatively to the xed rack 3 to cause the instrument to be automa"- ically trained in accordance with the established rate of change of bearing in the horizontal plane.

As previously explained the gear 20S is rotated from the differential 121 in accordance with the horizontal range rate of the target, that is, in accordance with ZR i. This movement of the gear is transmitted through a pinion 291 attached to one side 28S of a differential 238, the center 228" of which is attached to a shaft 2:19 which controls a cam and contact elements like those previously described and designated 213, 215, 215 and 216, but which for the sake of simplicity will be designated generally 380, which number is also applied to the wiring diagram of Fig. 2 wherein elements similar to those previously described for controlling the motor 211 are illustrated. In this case the circuit is established by the device 3D2 from the main 215 over one or the other of a. pair of conductors 3131, contact elements 352 of the control switch 221 and conductors 363 to the reversely wound field. windings of a motor 331i and thence through the armature to the other main 2221. As shown in Fig. la the motor 394 drives through a pair of gears S85, a shaft connected at one end through bevel gears 3131 to the side 298'" of the differential 239. The differential contact device 3DG and motor constitute a follow-up system for the quantity dRn similar to that previously dcscribed in connection with the quantity RiidB and imparts to the shaf a movement in accordance with the quantity CZRH.

Through a of bevel gears 39B the movement of the shaft is transmitted to a shaft SSS connected to the center' 31%' of a differential Bit shown on an enlarged scale' in 3 with other parts of the mechanism about to be described. One side 313" of the differential is connected through al gear train 241 to the shaft 23S which as previously described is turned .in accordance with the angie A representing the elevation angle of the target. The shaft 283 carries at its end a gear 312 meshing with the segmental gear portion 313 of a ring 314 to which is attached a U-shaped frame 315 havinUr a pair of guideways 31E on which is slidably mounted a biok en adapted to be positioned by a screw 3%8 mounted in the frame and actuated through a pair of bevel gears 319 from a shaft 328 supported in a bracket 321 attached to the frame 315. The shaft 32B carries a pinion C522 which meshes with an annular gear 325. The gear 325 is connected through c pinion 32:?, shaft 321 and pinion G23 to the second side 3 8"' of the differential 31H.

The gear 312 on the shaft 238 is connected through an idler Z329 to one side S32 of a differential 33D. The center 33 of this differential is attached to a shaft 33| which as shown in 1a. is connected through a pair of bevel gears 32, shaft 333, bevel gears shaft 335, to a gear 235 which may be shifted by a suitable device 331 into operative reiation to a motor fifi-3 or a crank S33. The crank. 339 is adapted to be set in accordance with the rate of climb of the targetY this quantity being designated 5C. and the motor forms part of the rate control mechanism of the instrument for this quantity. The shaft 333 is also connected through the bevel gears 349 to a dial 34| for indicating the rate of climb.

As shown most clearly in Fig. the third side 330'" of the differential 33C is extended and carries a gear 342 which through an idlei` 343 drives an annular gear 344 similar to gear 325. The gear 344 drives through a, pinion SI15, a shaft 346 mounted in' brackets 341 attached to one arm of the frame 315. Through bevel gears 348 i3 the shaft 356 drives a pinion shaft 3119 mounted between the outer ends of the arms of the frame Sie. The pinion shaft engages a rack 353 carried upon a pair of rods Btl extending from a member 352 slidably mounted in the block 3|'l for movement in direction at right angles to the direction of movement of the block on the frame M5. Attached to the rack 35o is a. rod 333 passing through the slotted vertical arm of a horizontally movable slide 35, and the slotted horiaontal arm of a vertically movable slide 355.

In the operation of the elements of the instrument that have just been described the rotation of the shaft 28S in accordance vith the elevation angle of a target Will through the pinion 3I2, gear sector 313 and ring 3M position the frame SI5 in accordance with the angle A, as shown in Fig. la as distinguished from Fig. 3 in which the frame is shown in its horizontal position as it would be for a surface target in which case the angle A equals aero. At the same time the shaft 288 will through gear train 3H drive the side 319 of the differential 310 and regarding its center as fixed the side i will through gear 32B, shaft 3? and gear 326, drive the annular gear 325 in unison with the ring 3N.. The shaft 223 will also through pinion 312 and idler 329 drive the side 33S of the diiferential 330 and regarding the center 330 as fixed the side 330'" Wiil 'oe turned and through the gears 32 and 3123 drive the annular gear 344, so that under these .conditions the ring 34d and the annular gear 325 34!! will be rotated in unison and the frame 3 l5 Will be positioned in accordance With the elevation angle of the target, no movement being imparted to the block 3V! or the rack 35i! relative to the ring 314. In other words, the two an- `cular gears 325 and 3M, the ring elfi and the frame 315 with its associated elements will simply turn from the position shown in Fig. 3 into the position shown in Fig. 1ct.

It has bee explained that the shaft 3ds is driven from the shaft 3% in accordance with the quantity dRH and now regarding the shaft as fixed the shaft 3F39 will drive the center 353 -i' di. erentiai tic and through the side 345', gear 323, shaft 32'! and gear 325 the annular gear 325 will be displaced with respect to the ring :ii-i which will now be regarded as fixed. The movement of annular gear 325 relatively tering Sid will through the pinion 322, shaft bevel 315.1 and screw 318 position the blocl; 3H in accordance with the quantity dBi-1.

.assuming now that the cranl; is turned in accordance with the est .cated rate of climb of the target and is operatively connected to the gear 325, the latter will through the shaft 335, bevel shaft bevel gears 332 and shaft correspondingly turn the center 333" of the di'flerentia Regarding the side 33S' of the differential being fixed since it is connected to the shaft 233 Which is now regarded as ed, the other side 333 will be turned to drive through the gears 36;2 and 33, the annular gear :fi-Li relatively to the ring Sie'. This movement of the gear Sie will be therefore transmitted to the pinienlab, shaft 3:13, bevel gears and pinion si it 3ds to position the rack 339 in accordance with the rate of climb of the target, that is in accordance with the quantity (ZC.

As a result of the operations described above the rod 353 .vill be positioned by the block 3i? in accordance with the quantity aRH and by the rack 358 in accordance with the quantity dC. The movement imparted to the rod 353 will position the slide 354 in accordance with the rate of change of direct range. dR, for this equals dBi-f cos A-l-dC sin A. as the mechanism is arranged.

The movement imparted to the vertical slide 355 is in accordance with the component of the targets travel across the line of sight in a vertical plane and is designated as This quantity equals dRH sin A-i-dC cos l in the arrangement of the apparatus.

The Vertical movement of the slide 355 is transmitted through a pinion 355 to one side 35i" of a dilerential 351, the center 35'!" of which is attached to a shaft 358 shown partly in broken lines in Fig. 1c which operates a contact device 353 similar to those previously deand represented diagrammatically as was the device Sci?. As shoe most clearly in Fig. 2 this device controls selectively circuits from the main BIB through conductors 353, contact elements 33! of the control switch 223 and conductors the reversely wound iield windings of motor 353 and the armature to the main Through a shaft and pinion 355 the motor -Gv drives the other Side 2531" of the differential 357 and also a slide As in the case of the quantaies RrZBN and dus the elements just described constitute` a follow-up system by which the movement of the vertical slide 355 is transmitted to the slide to operate it with increased power from the motor 3:33.

Attached to the slide 3G52 is a slotted bar the upper end of which is retained by a fixed pin SS. A pin 335 is attached to a member 310 slida'cly mounted on the horizontal arm of the member Eea, similar to the pin 23s and member 23a previously described. rfhe pin also passes through the slotted vertical arm of a hori- Zontally movable slide Sli. Since the slide 335i and therefore the bar 331' are positioned in accordance with the quantity RdA while the pin 3:39 positioned in accordance with the movement imparted to the slide 3H will be the product of these quantities or dA. The movement of the slide 3?! is transmitted by a pinion 32'2, shaft 373 and pinion Eid to the rack 28B which is connected to the ball carriage 285 of the variable speed device 233,

The roller 232 of the device will therefore be driven in accordance with the rate of change of angle A and will through shaft 221, bevel gears 2&3, slide 2558" and its center drive the shaft Bei-l since it is assumed that at this time the pointers handwheel 264 is not being turned so that the other side 2553 of the diierential is held xed. The movement of shaft will be transmitted through bevel gears 2li and shaft 2'1'2 to the worm 2.??3 to turn the sector 27E. and through linl; 2".:'5 and arm 2l@ cause the telescopes 6 and I to automatically follow the movement of the target in elevation as the mechanisni previously described caused them to be moved in train from the variable speed device 26. At the same time the value of the angle A will be continuously indicated by the dial 2li?, geared to the shaft 212.

It has been previously described that the slide a tl conta-cit eletne Y Y Y arni 32S is conductor Y39| freni whichV a branch 354 is displaced horizontally in accordance with the rate of change of range, The movement s transrn'ted through a which turns a dial 32'? s oi this quantity. The ther end a pinion Si?. meshing a rack connected to the hall carriage f a variable'Y speed device 33! consisting of diri/'er Vt constant speed the'inotor connected to d shaft n illu.

D ic other Y.side 1 `ven and r Elie, the t niaticallv vice 33:' as tv aia; Z253 cn the end of shaft is a result the tele-s3 in t ln and in range l Y he automatical 'driven ion and the ronge dial 'i i the estimated moveents of tained upon the -ornspcnd to tl e initial settrng o" .l not t so'that the observers :vill notice target from thefc 'oss Wires of their and the range indicated 'n'pracct al ian s t Mr-pes inay justed to caoseitheir lines o1' sit to be in Ythe tex in both 'nainesl ation and the Yrange hidicated.

in connection with the description o this mechanism, which will hereinafter berelerred Lto generally as the rate control mechanism, refere ence i nl he made to Fig'. 5. Any target or wind angle referred toa horizontal plane will ce in one ouadrants, the first, Qlybeing that be- '2, Q3 and Ql Vfollowing the around the circle. a rst the mechanism by which th from the vertical cross wire of his telescope, he turns his handwheel IQ in the proper direction to shift his telescope to bring the target on to this cross wire. This is accomplished through the nevel gears ii and l2, the Side i3 o e-ential 1S and the center for the other iay at t".is time be'regarded as nxed y driven. The movement imparted to the center o1 the differential Vvvill through theVY shait iis' and pinion ia'turn the instrument inVV train to bring; the target unto the vertical cross WireY L In order, however, that the condition set up by the trainer ma" ccuitinue, a correction to the rate or train of the instrument is necessary. For this purpose the handieo the trainers handrvheel is provided with a suitable switch SBB which is shown in connection With the circuits of the instrument in c'. 2. The switch is connected to the main 258 and :carries a Contact element adapted to co-act with another Contact piece mounted on aexi'ole arm 339 and below which is t 39B. 'Connected toV the a0 331 leads to the electro-magnet 392 of a clutch 353 shown in iiig. ld and another branch 391 leads to the electro-magnet Bei of a clutch 395 also shown in Fig. la. The circuits of the electro magnets are completed through conductor 393 to the main 224 of Fig.r2.

As shown in Fig. la the eiectro-inagnet of the clutch 333 is connected to one side of a'ciifferential 3S? and the armature 35u of the clutch carries a gear which meshes with a gear 339011 the shalt between the slides il and Z55. The other side 35? of the diierentiai is connected hy a pair of bevel gears im to a shalt which at Y its other end carries a bevel gear liljmeshing tending '-:o a sWi-tfh 45:2. YThe shaft no3 carries an arzn having a pm extending from its outer end.n An arrn tail is loosely pivoted on che shait and carries a pin i extendi parailel to the pin 43S. A spring 410 is coiied about the shalt et and has one of its free ends extending upwardly in contact with one side or' each of the pins 5 andi-eee and its other free end extending upwardly in YContact with the opposite sides of the pins. The arm'li? is centralized by a, C- spring 4i i suitably anchored by having its upper ends engaging notches in opposite coges or' the arm ig. The ends of C-spring 4i' l also normallyf engage opposite sides of a xed abutment bloei; 5b. The arm Iir''i carries an insulated contact Gili which as shown in Fig. 2, in which the switch liti; is shown diagrammaticallygis connected by a conductor l to the ncontact element 1353 of the trainers control switch. The contact l2 is adapted to engage one or the other of a pair oi contacts fil according to the dirC tion 0i" movement oi the arm upon which it is carried. In sordoing, the arm 357 displaces one end or' the C-spring I, the other end or' the spring being held from a following,- movement 'oy the abutment bloei; 58 thus storing energy in the spring which is used to restore the displaced arni il to its neutral position when the clutch CBSStis not energized. i n

As the trainer turnshis hand wheel in making correctional adjustments he ll close nis control switch 33a; thereby energizing the clutch 35.3 so that the side Si of the direrential ii.' will be operatively connected to the shaft E55. The rotation of his hand Wheel will ce transmitted through the 'Devel gears il, l2 and 5.62, shaft 4i?! and 'oevei gears to the side t" of the diiierential Regarding the side Sl' as fixed since it is clutched to the shaft 253 tie center 3&57" will be turned and throngA short tot the arm Q5 will be turned and through the pin flot one or the other of the upwardly extending ends of the spring d I will be moved to wind the springr and'cause the other end of it to move the pinV Lz and the arm iol against the eii'ect of the centralizing C-spring Hi until the contact element i I 2 comes into engagement with one or the other of the contacts 'l. The spring Ait Vwill permit additional movement of the shaft .353 vith respect to the arm d of the Contact device untii movenient of the shaft is checked.

i the lower-end Yof the control switch 22|, so that 75 iwhen the :trainerfg control switch 338 is closed a operation of the i the pin circuit is established from the main .2|8 through the switch, contact arm 339, conductor 39 switch M', conductor M5, and electro-magnet 11H to the main 22s. The resultant actuation of the control switch 22| will, among other things, separate the contacts 22B and 222, and 222 and 221 to disconnect the RdB motor Il from the contact device 2 3 and put it under the control of the contact device 04. For this purpose the contacts lift are connected by conductors MS toa pair of contact elements i' o the control switch, one of which coacts with the contact element 222 and the other with contact element 221 controlling the circuits 223 and228 respectively to the motor 2|?.

Therefore when thecontact device is actuated by the trainer in making correctional adjustments in one or the other' direction the motor 2|? will he energized and through the s v229, 23, shait` 23| and pinion 23d will inove the slide 235. TheV movement of the latter will through the bar 236 and pin displace the slide 25|. The movement or" the latter will through pinion 252 and gear 322 on shaft '253 turn the side 38?' of the diierential since the .clutch is energized. Regardingr the other side 3.2i". of the differential as red the center 39? will be turned and thereby theshait G3 in a direction to break the control circuit of the motor 2|? which was established through the contact device A|5043. There is thus provided o.n other follow-up control for the inotor Eil the rotation of which through slide 235, bar pin 235i, slide 25|, pinion 252, shaft pinion 2.5:@

transmitted to the slide 255 as previously described in connection with the initial training instrument. Through the mechanism previously described as ceing actuated from the slide 255 including the secan-t multiplying gear 253 the slide 259, the pin the slide 22E', pinion 29| and shaft 222, the ball carriage 29 or the variable speed device will he shifted from the position which it occupied during the previously described operation of the apparatus. This will cause an alteration in the rate, .at which the instrument will se trained by the variable speed device, to correct for the error discovered by sighting on the target.

In order, however, that the rate may be maintained in its proper corrected condition during the subsequent operation, it is necessary to adjust the position of the pin S3 for the target o1' i4!) for wind. For this purpose the transfer of control by the switch 22i of the RdB motor 2|? from the cam switch 2i3 to the rate r control switch alla simultaneously puts the course niotor B3 or the speed motor l1 under the control of the cam switch 2l3. Referring to Fig. la, it will be seen that the actuation oi' the RdB motor 2|? moves the slide 235 and the parts connected Ythereto and also drives the shaft 23| and through the pinion 232 theside 211'. of the differential 2H. Regarding the other side 2H' of the differential as being fixed the center 2| l" will he turned turning the cam 2|S to throw switch arm Zl into engagement with one of the other of these conductors to conductors 422 leading to the quadrant switch l; The mechanism of this switch will hereinafter be described in detail, but at present it will be stated that it has a shaft having four insulated sections each carri ing a. cylindrical element having an arrn adapted 'to engage ixed contacts arranged around the shaft. of the conductors .22 is connected to the brush associated with the bottoni arm which is thus electrically connected to the conductor. The companion conductor 422 is electrically connected by a similar arrangement to the next arzn 425.

The arms i213 and 1325 are shown in the quadrant l position where they are in engagement with contacts 25 and 42? respectively. From contact 425 a conductor 12S leads to one field winding oi the speed motor ill. From contact Y122i a conductor 429 leads to a conductor 53) from which a conductor 133| leads to the other field winding of the speed motor. Each circuit is completed through the armature of the motor vto the negative main 2231.

If the shaft of the quadrant switch Toe re garded as turned through 180 representing quadrant 2 the arms 2d and i325 will in engagement with contacts 23' and 2T respectively. The former of these contacts is con nected to the conductors 1135 and 3| leading to the motor Hl, while the latter is connected to the conductor 1528 leading to the motor. It rollows, therefore, that when the arms and i525 ci the quadrant switch are in engagement wi n the contacts 22e and 2'1" respectively the field windings loi' the motor lil will he connected to the cam switch EIS reversely to that in which they are connected when the arms occupy the positions shown in Fig. 2.

In quadrants 2 and 4 an error in the established rate of change of bearing oi' the target will be due primarily to errors in the estimated speed of the target while in quadrants l and 3 such errors will be due primarily to errors in the estimated course of the target. Accordingly when the course of the target lies in quadrants 2 or 4 the speed motor Hl will be employed for adjusting the position of the pin S3 to maintain the corrected condition of the instrument while in quadrants l 'or 3 the course motor SB will be employed for this purpose.

Fig. 2 shows that if the arin :i211 be turned 90 from the position shown into engagement with a contact 26 a circuit will be established rroin the conductor P322 connected to the arrn 2e through a conductor from which a conductor 335 leads to one field winding of the course motor When the arm 425 of the quadrant switch occupies a similar position in engagement with the contact 427" a circuit will be established from the other conductor 5:22 through a conductor A from which a conductor i535 eads to one contact Q31 of a relay 338 which will be described hereinafter. The other Contact B of the relay is connected by a conductor M) to the other held winding of the course motor 83.

As in the case of the connections through the quadrant switch between the conductors 22 and the field windings or the motor i i1. there will be a similar reversal of connections 'between these conductors and the field windings of the motor 83 when the arms 24 and i325 are in engagement with contacts 428'" and 2727" respectively, as will be obvious when the circuits are traced.

A brush coacts with the element. One

fihi.

aecaaec If the target angle be in quadrant 2 or quadrant 4 in which cases the speed motor l Il would be controlled from the switch 2|3, the handle |09 will be manipulated to shift the arm IEE to bring the gear I I3 into engagement with the gear I|4 on shaft II5 connected to the motor. The latter will through 'the shaft and gears drive shaft |05, gears |05, shaft 5:14, gears E93, shaft |02, gear |0I and the side 25" of the differential 95. Assuming its center SS to be xed since it is connected to the target angle gear the other side 08 will be turned to turn the target speed gear 95 to alter the position of the pin 93 in accordance with the correction required in the estimated speed of the target.

On the other hand, if the course of the target be in quadrant l or quadrant 3 the target course motor 83 would be controlled from the switch 2|3. The handle 75 will therefore be manipulated to shift the gear T9 into engagement with the gear 80 so that the motor will through shafts 8| and 1| drive the center l0 of the differential 10. Assuming the side 'I' to be fixed since it is geared to shaft 53, the other side will be turned to turn the target angle gears 85 and Si? and the target dial Sl. This will alter the position of the pin 93 in accordance with the correction required to the estimated course of the target to compensate for the error which has caused the deviation of the target from the vertical cross wire of the trainers telescope.

In both cases the resultant alteration or' the position of the pin 93 will produce a corresponding displacement or" the RndBr slide l i8, turning through pinion |23, shaft |2| and gears |22 the side |23 of differential |23. Regarding its conter |23 as xed the other side |23 will be driven and through shaft 232 and pinion 2HEt drive the side 2|| of differential 2H. Regarding the side 2|| as xed, the center 2| I will be turned to rotate the cam 2 I3 and break the control circuit from the arm 2|5 to the motor 83 or the motorl I I1 as the case may be. In other words, the elements above described constitute a follow-up systern for adjusting the speed or course of the target under the control of the trainer, so that after the correcting operation has been performed by him the telescopes -3 and 'I will continue to be automatically driven in train but will be more accurately maintained upon the target.

It will be understood that in practice corrections are applied to the instrument from time to time as required to maintain the lines or" sight or" the telescopes accurately upon the target. rEhe ratios used in the gears which are interposed between the trainers handwheel and the switch 404 will determine the magnitude of the correction which is applied for any given movement o1' the trainers hand wheel and can be adjusted for any desired time interval between corrections to enable most efficient operation of the instrument.

In the foregoing description of the rate control features of the invention insofar as training is concerned, it has been assumed that the course and speed of Own Ship and direction and velocity of the wind are accurately known so that pin IB'I which controls the Own Ship slides |94 and |95 and the pin |50 which controls the wind slides and are accurately positioned in accordance with the quantities which they represent. The course and speed of Own Ship may ordinarily be accurately determined, but there may be errors in the estimates of the direction and velocity of the wind. Assuming therefore that the angle and air speed of the target are accurately known the pin |40 can be repositioned by the rate control mechanism in a manner similar to that in which the pin 93 is positioned. Insofar as wind is concerned it bears the same relation to the quadrants of Fig. 5 as does the movement of the target. That is, in quadrants l and 3 errors in the positioning of the pin |40 will be due primarily to errors in the wind angle, while in quadrants 2 and 4 such errors will be due primarily to errors in wind velocity.

The control of the course motor 83 or the speed motor by the cam switch 2 |3 under the control or the trainer has been described and the circuits have been traced through the switch 42| and the quadrant switch |00. Operations in all respects like those previously described in connection with the rate control take place insofar as Wind is concerned with certain exceptions as will now be noted.

in the first place the svitch 42| is thrown to its left hand position so that the conductors 420 are connected through the two upper blades of the switch to a pair or' conductors 44| electrically connected through brushes 'to the two lower arms 442 and 443 of the wind quadrant switch |62 which is in all respects like the quadrant switch |80, these arms being shown in the quadrant 4 position like the corresponding arms 424 and 425 of quadrant switch |60.

n this position the arm 442 engages a contact 444 from which a conductor 445 leads to a conductor 345 connected to the conductor 428 leading to one field 'winding of the speed motor l I?. Similarly the arm '343 in the position shown engages a Contact 447 which through a conductor 443 is connected to the conductor 43| leading to the other field winding of the motor II'I. As in the c of the quadrant switch IDB when the arms 442 and 443 occupy positions 1S()c from those shown, that is the quadrant 2 position, they engage contacts 444 and 441 respectively. From the former Contact a conductor 443 leads to the conductor 448 and from Contact 447 a conductor 450 leads to the conductor 44S. Therefore as in the case of the quadrant switch |00, when the arms i512 and 443 are in engagement with the contacts G44' and 441 respectively the eld windings of the motor will be connected to the earn switch 2|3 reversely to that in which they are connected when these arms occupy the positions shown in Fig. 2.

Also as in the case of the quadrant switch |00 the arms 442 and 443 will when turned from the position shown engage contacts 444" and del respectively. Frein the former of these contacts a conductor 45| leads to the conductor 434 connected to one of the eld windings of the course motor S3. From the contact 447" a conductor lz-52 leads to the conductor 435 to establish a circuit from this contact through contacts 431 and 439 or" the relay 433 and conductor 440 to the other iield winding of the course motor 83.

As in the case of the connections through the quadrant switch between the conductors MI and the eld windings oi' the speed motor Ill, there will be a similar cwersal of connections between these conductors and the field windings of the motor B3 when the arms 442 and 443 are in engagement with contacts 444' and 4.41" respectively located opposite the contacts 444" and 44'1 as will be obvious when the circuits are traced, I

In addition to shifting of the switch 42| to substitute the quadrant switch |62 for the quadrant switch |00, it is also necessary to connect astma;

:2l the motor 83 to the shaft |3| and the motor H7 to the shaft |50 through the clutches |36 and |5| respectively. In Fig. lb the motors are Shown connected in this manner so that they are then selectively under the control of the switch 2|3, in accordance with the condition of the.

quadrant switch |62.

As in the case of a target angle lying in quadrant 2 or in quadrant 4 the speed motor H7 is under the control of the cam switch 2|@ when the wind angle lies in either of these quadrants. The motor drives through shaft H5, bevel gears |53 and |52, clutch |5I, shaft |58, bevel gears |49, shaft M3 and bevel gears |47, the side |145 of the differential |45 and its other side |45, since the center |45 may be regarded as fixed as it is connected to the wind angle gear |37. Therefore, the wind velocity gear |42 will be turned to position the pin 48 in accordance with the correction required in the estimated velocity of the wind.

If the wind angle be in quadrant 1 or in quadrant 3 the course motor 83 is under the control of the switch 2 i3. The motor will drive through shaft 8|, bevel gears |28 and |29, clutch |35 and shaft |34, the conter 58" of differential 59.. Regarding its side 58 as fixed, its other side 58" will be turned to turn the wind angle gear |37 through the extension |35 and pinion |36. This will alter the position of the pin ie in accordance with the correction required in the estimated direction of the wind.

In both cases the resulting alteration of the position of the pin |42 will produce a corresponding displacement of the RHdBW slide |70. This will through pinion |72, shaft |73 and bevel gears drive the side |75 of differential |75. Regarding its center |75 as fixed, the other side |75 will he driven and through the gears the shaft 29| will be rotated. Referring to Fig. la, this will turn the center |23 of differential |22- and regarding its side |23 as fixed, its other side |23 will be driven to drive shaft 262 and pinion ZIB and the side 2H of diierential 2| i. the center 2 l I will be turned to rotate the cam 2|3 ancL break the control circuit from the arm 2I5 to the motor 83 or the motor H7 according to which one is in operation.

Simultaneously with the operations described above the wind velocity dial |59 will be repositioned in accordance with the corrected wind velocity. When the course motor 83 is being employed there will be a repositioning of the wind angle ring |68 in accordance with the corrected wind angle through bevel gears |63, shaft |64, bevel gears |65, shaft |66 and pinion |67, so that its index |69 read against the ring 58 gives the true direction of the wind.

Not only will there ordinarily be a deviation of the target in train as a result of errors in the estimates used in the preliminary settings of the instrument, but there will be corresponding errors in elevation which will be manifest to the pointer by the departure of the target from the horizontal cross wire of his telescope showing that the instrument is not accurately following the movement of the target in elevation. Upon observing a deviation of the target from the horizontal cross wire of his telescope the pointer turns his hand wheel 264 which through bevel gears 25E and 267 will turn the side 268 of the differential 25B. Regarding the other side 268'" as xed or positively driven at this time, the center 258" will be turned and through the shaft Regarding the side 2|| as fixed,

25E, bevel gears 27|, shaft 272, worm 273, gear sector 274, link 275 and arm 27e, the telescopes may be adjusted in elevation until the pointer has restored the target to the horizontal cross wire of his telescope. Y

The handle or' the pointers hand wheel 264 is provided with a control switch 453 similar to that provided for the trainer and which as shown most clearly in Fig. 2 coacts with contact arm 454 and a contact element 455 from which a conductor 455 leads to the contact element 457 of a switching device in all respects like 404 and which therefore will not be described in detail but merely designated by the reference number 457.

The actuation of the pointers control switch 45e establishes a circuit from the main 2|8 through a conductor 456', contact arm 454, conductor 39| and conductor 39| to the electromagnet 324 of the clutch SSS previously referred to. At the same time there is established by means of the pointers control switch the circuit of the electro-magnet 4|7 of the control switch 22| independently of the establishment of this circuit by actuation of the trainers control switch f' 2, this circuit being established through the switch 4|5' and conductor 4|5 to the main 224. This organization of the electro-magnet 4|7' causes the control switch 22| to be shifted by the pointer to change the circuit connections as will be hereinafter described.

The electro-magnet element 394 of the clutch 335 is attached to a shaft 458 connected by bevel gears 15E to one side 460 of a differential 468'r the center of which 459" is connected by a shaft 45| to the contact device 457 by which the latter is actuated in the same manner that the contact device 481i is actuated from the shaft 403. The second side 465'" of the differential |30 is connected by bevel gears 462 to a shaft 463 passing through a bearing in the standard 5 and connected by a bevel gear 464 to the bevel gear 257 adapted to be actuated from the pointers hand wheel 254. The armature side 395' of the clutch 395 is connected through bevel gears 465 to the shaft 373,

As the pointer turns his hand wheel 254 to bring the horizontal cross wire of his telescope Y on the target, he will through bevel gears 255, 267, 554 and 482, and shaft 463 drive the side 460'" of the differential 455. Assuming the clutch 365 to be energized by the closing of the pointers control switch 453, as previously described., the side of the dilferential which is connected to the clutch may be regarded as fixed so that the center 451i will turn and through the shaft 46| actuate the contact element or" switch 57 in one direction or the other to energize one or the other of a pair of contacts 466. The contact element of switch 45'. as previously described is connected by conductor 456 to the now energized contact element 455 of the pointers control switch. From the contacts 456 the circuit will continue through one or the other of a pair of conductors 457, a pair of contact elements 488 of the control switch 22| which at this time is held in its lower position by the electro-magnet 417 and then through one or the other of the pair of conductors 362 to the RdA motor 363 and thence to the main 224.

As a result of the operations described above the motor 36,3 will be driven in one direction or the other and through the shaft 354 and pinion 365 will move the slide 366. The movement of the slide will through the slotted bar 367 alter the position of theipin 369111 a lhorizontaldirecn i tion thus impartins: a similar movement to the slide 37|. Through the Vpinion Teil2, shaft 373.

pinion Bl, the ball carriage of the variable non speed device to rate at which the vation from the device. shaft S73 will through the bevel the energized clutch 395 drive th will be altered to change the telescopes are driven in ele- At the same time the eears fl'and side Gil'V of the Ydifferential 65.' Regarding tde side 45S as fixed the center fte will be 'iven to actuate through the shait 45| the switch 5l to breal; the circuit of the motor 333 so tithe parts of the instrument will be in a condition of adjustment for the corrected rate ci change of elevation of the target.

As in the case of the train .ients of the instrument. it is necessary to rcposition the elements controlling the e evation rate in order that the correction applied as above described may be maintained. The changes in tion of a target in elevation at lov: angles, for instance below 40. will be' due primarily to its deviation from a horizontal cour e, that its climb. At higher angles, however, the speed or course of the target will have more effe At upon variations in anaal-ar poshion. Therefore in the instrument the maintenance f the corrected condition is produced by operating the rate of climb motor 338 for atarget'at a low angle and by the speed: motor or the course motor 3S for a target at a high angle. it is accordingly necessary to provide a high and low1 angie switch 4GB as shown'in Fig. 2.

During the preliminary setting of the instrument as described above the Rall-i motor 35S is controlled from the switch 3 3 but the shift# ing of the control switch 22KL q`=l disconnect the switch 359 from themotor by breaking theV control circuits at the contacts Gili. The conductors 350 leading from the switch vigil then be connected through the contacts 35i which are connected to the bar 22|' of the control switch to contacts 410 from' which conductors 111| lead to two of the blades '22 of the switch 459. When the switch is thrown to the right hand or low angle position the circuits continue through contacts i373, a pair of conductors 7:1, a pair of contacts 475 and a pair of conductors 415 to the reversely wound field winding of the dC motor 33B after which the circuits continue through the armature to main 225.

Assuming that the shifting device is in a position to connect the gear 336 to the motor 338. the latter will through shaft bevel gears 334, shaft 333, bevel gears 332 and shaft 23| drive the center of the differential 339. Regarding the side 330 of the diierential as being,r xed since it is connected to the elevation shaft 285 the other side 330'" will be turned to drive, through the gears 32 and 343, the angular gear 344 relatively to the ring 3|. As heretofore explained this movement will be transmitted to the rack 3551. rlhis will alter the position of the rod 353 and displace the RdA slide E55. The movement of the latter will through pinion 356 move the side 357? of the differential Y'and regarding its side 351'" as fixed, its center S57" will drive through the shaft 358 the contact device 359 in a direction to break the circuit of the motorV 338 which has been under the control of this device during the operations just described. The elements of the instrument are accordingly repositioned in accordance with the correction the angular posirequired in orderithat the telescopes may ace curately follow the movement of the target in elevation.

The mechanism for correctingr the range rate will now be described for a target at a low angle. In this case if the course ofrthe target be in either'quadrant l or quadrant 3 variations in speed will produce the major effect in changes of range rate while in either quadrant 2 or quad: rant 4 changes of course will be the determining factor. r

As previously described the estimated range of the target is set into the instrument by the handle 21M and the shaft 245. The handle is provided with a switch :i' which as shown in Fig. 2 carries a contact element 418 to which the conductor M5 is connected. This contact element is normally in engagement with a contact element dlg from which a conductoivfii leads to an electro-magnet 43|, the other terminal of whicnis connected to the main 224. rlhe switch lill carries aipair of lower contact elements adapted to engage a pair of contacts 4.52. the right hand one oi' which is connected'to the main 2li] and the left hand one by a conductor 483 to the coil of an electro-magnetic clutch 434 from which the circuit is continuedY through the main 224.

As shown in Fig. la the electro-magnetic element of the clutch 485 is connected to a shaft t5 connecte-:l by a pair of bevel gears Se to the range shaft 21l5. Thenrmature element El of the clutch is slidably mounted on a shait which by bevel gears is connected to one side of a differential the center F535" of vfhi connected to a shaft 53| for operating a s. 92 similar to the switches 11.54 and ll previously described. fhe other side 499' of the di .erential is connected by gears V1293 to the shaft 375 through which the position of the ball carriage of the variable speed device 35| is adjusted. As chown most clearly Fig'. 2 the arm Yof the switch |82 is connected to the main 2|8. A conductor 'iid leads from the main to a contact element 5350i the control switch 22j. The contacts i218 with which the switch f192 coacts are connected by a pair of conductors el to the blades i398 of the high and low angle switch 669.

When the range switch il?? is closed a circuit will be established from the main 2|@ through right hand contact element 482, the blade of the switch, conductors 4 i 5 and 4 I 5, electromagnet 4 il to the main 224 to energize the electro-magnet to shift the control switch 22| into its rate controb ling position. At the same time a circuit will be established from the main 212i through the contact elements A82 andthe blade of the switch, through conductor 1233 and the electro-magnetic clutch 484 to the other mairL224. Therefore'the movement imparted to the shaft 2115 by operation of the handle 244 will through bevel gears GSE, shaftialia, energized clutch [l5-4, shaft 43S and bevel gears 489 be transmitted to tl e side 690 of the differential 495. Regarding the side 499'" xed since it is connected to the shaft 312B, the center ABQ" will be turned and through shaft. 49| the arm of the switch .'182 will be turned to engage either one of the contacts 96 to establish a circuit over one or the other of each of the following pairs of elements; conductors 92, bla-des 498 of the switch 469 which at this time is'in its low angle position, contacts SQ with which the blades are in engagement, a pair of conductors 50D, a pair of contact elements 59| of the control switch|22| and one or the other of the conductors 23113 leading to the field windings of .25" the dRH motor 334i from which the-circuitisgcompleted through the armature to the main 224.

The motor will then through' gears 3,05, shaft 305, bevel gears 3&3 and shaft 339 turn the center 3|iof diierential 35a. Regarding the side 3|0 of the diierential as fixed the otherside 3 23 will be turned and through the gear 328, shaft 32? and gear 325 the annular gear 325 will be turned. Regarding the ring 3 i4 as fixed, the relative movement between it and the gear S25-will cause a dis-- placement of the block 3 i l by the pinion 322, shaft 320, bevel gears 3|J and screw 313. This will result in a displacement of the rod 353 to shift the dP., slide 354. The movement of the slide will be transmitted through the pinion SEE to the shaft 315 to alter the position of the bail carriage 33:) of the variable speed device 35|, thereby altering the rate at which the roller 333 drives the shafts 334. and 330 and the inrerse range gear 243 and the range dial 255 through the sides 2555" and 24E of the differential '245, the center being regarded as fixed.

The shaft 3FG will also through gears 493 drive the side 5.55" of the differential 455) and regarding its other side 450 as xed its center 493" will be turned and through the sha-ft 39| will break the control circuit ci the switch |532 to dei-energize the motor In order, however, that the corrected range condition may be maintained the heretofore del` scribed movement of the shaft 335 will also be transmitted through the bevel gears 33'! to the side 298'" oi the differential 233. Regarding its other side 298 as fixed itsv center 238" will he turned to operate the switch Siiithrough the shaft 299'. Reference to Fig. 2 shows that the shifting of the control switch B2i has at the contacts 392 'broken the control circuits from the switch 300 over conductors 33| to the conductors 333 leading to motor Sail and has established circuits from the contacts 352 over the conductors 502 leading to the two lower blades of switch 421. When the witch is in its right hand closing position the conductors 532 are connected through the blades to two conductors the left hand one of which is electrically connected to an arm 524 of the quadrant switch |33, while the right hand one is connected to a similar arm 535. As in the case of the arms 24 aud the arms 5541 and 505 are adapted to engage contacts arranged around the shaft of the Quadrant switch. The contacts with which the arm 55 coacts are designated 505, 53S, ESG and 5351" in the order in which they are arranged around the shaft. The contacts with which the arm coc-.cts are designated 5522531, E51 5131"' in their order.

In view of the assumed angle or the target the arms of the quadrant switch should be regarded as occupying their quadrant l position, that is with the arm Eet in engagement with contact 506" and the arm E35 in engagement with contact 501". From Contact a conductor 508 leads to thcconductor 42S which is connected to one of the field windings of the speed motor l i?. From the contact 5cl a conductor 533 leads to the conductor Si leading to the other field winding or" the motor ||'i.

When the arms 534, occupy positions 18' from those assumed above, that is, when they are in the quadrant 3 position, theyy will be in engagement with contacts and 531' respectively. Contact is connected to the conductor 43| leading to thc motor l il and the contact 501" is connected to the conductor 42S lead ing to the same motor. In other words,` the contacts 583'" and' 501'" are connected'v to theconductors leading to the motor in reverse order; to that iii-which the contacts 503" and 501. are connected, so that the direction of rotation of the armature of the motor will be reversed when thearms 5mi and 505 occupy their quadrant 3 position as compared with their quadrant` l; position.

When the arms 504 and 505 occupy thefposie. tions shown in Fig. 2, that is, the quadrant pcsi tion, they are in engagement with contacts 506, and 501 respectively. The contact 50S is connected to the conductor 436 from which the ciI-, cuit extends through contacts 431 and 439 ofthe relay 438 and conductor 440 to one field winding of the course motor 83. The contact 501'is con;

nected to the conductor 433 which is connected to conductor 434 leading to the other eld winding of this motor.

When the arms 504 and 505 occupy positions 180 from those shown in Fig. 2, thati is, the

quadrant 2 position they are inengagement withA contacts 506 and 501 respectively. The former of' these contacts is connected by a conductor- 510 to the conductors 433 and 434 leading, to` the motor 83. The conductor 501 is connected-Y bya conductor 5H to the conductor 43S leading to the same motor through the relay 438. By virtue of this arrangement the connectionsto the motor 83 will be reversed when the the arms 40.4 and 405 are turned 180 from. the positions shown in Fig. 2. y

On account of the connections just described the speed motor H1 will be controlled fromA the switch 330 over conductors 30|, contacts 302. conductors 552, switch 42|, conductors 503; and the quadrant switch |09 when the target angle is in quadrant l or in quadrant 3, while. the course motor 83 will be controlled from the switch 300 over the same circuits when the target angle is in quadrant 2 or in quadrant 4. In the case of atarget angle in quadrant 1 or in quadrant 3 and assuming that motor ||1 has been connectedto the shaft |03 by operating the clutch |01 and regarding the center 96 of the diiferential 35, as being fixed, its sides 95 and 96 will be turned bythe motor through shaft |35, gears |05, shaft |04, gears |33 and shaft |02 to turn the target speed gear 95 to reposition pin 93 in accordance with the corrected condition of the instrument. The displacement of the pin 93 will move the slide ||9 and through pinion |24, shaft |25. and gears |25 the sides |21' and 121'" of the differential i! will 'ce turned, its center |21 being regarded as fixed. Through gears 201, shaft 208, gears 209 and 291, the side 230 and center 298 of diiferential 29S will be driven since its side 298'" may be regarded as xed. The movement thus imparted to shaft 299 will operate switch 300 to open the circuit of motor i i1,

If on the other hand, the connections through the quadrant switch are such that the course motor 83 is under the control of the switch 3.00 the motor will through shaft 8|. gears S0 and 19 which at this time are in engagement, clutch;12 and shaft 1i turn the center 10" of the differential 10. Regarding its side 10' as nxed since it is connected to shaft 53 through pinion 65 the other side 10 -Will be turned to turn the target angle gears 85 and 90 and the target dial 8,1 to

reposition the pin 93 as to course in accordanceA with the corrected condition of the instrument. As before, the movement imparted to the slide ||9 by the repositioning ofvthe pin will through dierentials i 27 and 29B break the control ,It the motor B3 at the switch 39".

each or the cases described above the pin i. -enositioned vertically in order that the eleci' the instrument which are actuated. in accordance the range of the target may be maintained in their corrected condition after the range operator opens his switch dll to restore the instrument to its nrst described condition of i :i its range elements are auicallfyv and continuously operated.

For a at a high angle, for instance above 40, and having a course in quadrant l or quadrant 3 the errors in its rate of change in elevation will he due primarily to errors in the estimate cf it.: speed, while in quadrant 2 or quadrant i the errors will he due primarily to errors `ts estimated ourse. These conditions cor- .'cspcnL to those of the "rors in range rates for ow vitudcs. The co; ections for errors in elevation at h'ch angle are therefore applied over thc same circi s and through the same elements as were the range rete corrections previously described, for when the switch 5S is thrown to its operation in wl' switch oir u acts 0l' the control switch 22l a e conductors fill leading to the blades il? of the switch 69 which at this time are in engr, t with contacts 599 to which the conductors ed connected. These conductors as previously described control the motor 3% which controls the ewitclfrom which circuits are established over he conductors S and the contact elements S52 of the control switch 22i to the conductor" 52 and Edil leadingr to the quadrant switch The latter will as previously described in connect-ion ..vith the range rate control at low angles control the course motor 83 or the speed motor H7 according to the quadrant in umich the target angle lies to reposition the elements of the apparatus to maintain it in its corectcd condition after the rate controlling operaion has been performed.

Similarly for a target at a high angle the error in its rate change of direct range will be duc primarily to errors in its estimated rate of climb for all quadrants. Therefore, when the switch 153.. thrown to its high position the conductors 29? loading lfrom thc switch :92 which is under the control or thc range operator as previously.1 described "l ce connected through the blades :E23 the switch. contacts l5 and conduct-ors o the rate or clin o motor 333 so that the subsvment operation of the apparatus and the tioning o' its elements by his motor will take cinco s heretofore described in connection i. he corrections for altitude under the control or th switch .'35'1 when the switch i539 is in its low angle position.

In other words, the switch i369 in both of the cares considered above simply interchanges the rontrols from the switches 359 and 492 from thc-se required for low angles to those required for high angles or vice-versa because the contacts Q73 with which the blades fll'Z are in engagement in the low angle position of the switch are connected conductors llt to contacts i515 with which the 'blades 11.53 are in engagement in the high angle cosl 'on of the switch. Similarh7 the contacts 9S with which the blades 498 of the switch are in engagement for a low angle are connected by conductors 50D to contacts E' with ,which the blades 522 are in engagement when they are in their high angle position.

The manner in which the nin ifi!) controlling the wind slides HD and il! is repositioned 'oy the rate control mechanism insofar as training; is concerned has been described. The instrument also provides for a similar repositioning of the pin insofar as corrections in the vertical plane of sight is concerned. With a wind angle in quadrants l or 3 errors in the positioningr ot the pin are due prmaily to errors in the estimates of the velocity of the wind. In quadrants 2 or e such errors are due primarily to errors in estimates of the direction ot the wind. At low anges the wind errors are znaniest as errors in range, while at high angles they are manifest to the pointer as errors in elevation like those for a target at a high angle. inasmuch as wind has no appreciable con oonent corresponding to the rate of climb of a targe corrections in elevation or range hich control the rate of climb have no corresponding control on the wind.

Therefore errors in the estimated direction and velocity of the wind at low angles are corrected hy the same elements as described in connection with the range rate correction for target at a low angle exceot that the switch if!! is thrown to its left hand circuit closing position to connect the conductors :3BE to condu tors El? leading to the wind quadrant switch |52 where they are electrically connected through brushes to arms 5i?.- and iil, each of which is adapted to coact with four contacts arranged around the shaft of this switch.

Similarly errors in the estimated direction and velocit;J or' the wind at high angles are corrected hy the same elements as described in connection with the elevation correction ior a target at a high angle with the exception that the wind quadrant switch 152 is used.

Since in both cases the switch 385 controls the motor 83 or the motor IH according to the quadranta in which the wind angle lies, it is only necessary to describe the elements of the wind quadrant switch which have not hcretotorc been referred to and their connections to the motors.

The contacts with which the arzn 5175 coaots are designated SI5, SiS, 5l5' and Ei'" in the order in which they are arranged around the shaft. The contacts with which the crm Ell coacts are designated l, Sid and 565'" in their order. Contact SiS is connected by a conductor 517 to the conductors and :E36 throuch which the` circuit continues through contacts El and ot the relay A33 and conductor fl-' to one field winding of the course motor 83. The Contact 515' is connected by a conductor 5H! to the conductor 45! which is connected to conduc'tor :i3d leading to the other winding of the motor 83. The contact 5l-5 is connected to the conductor 45D which is connected to the conductor 46 leading to one field windinc or the speed motor H1. The fourth Contact 5i?" is connected to the conductor Sd w" ich is connected to conductor G3i leading to the other eld winding of the motor H7.

The contact 51S with which the arm 5 lf3 coacts is connected by a conductor 519 to the conductor 52 leading to the conductor 34 connected to one eld winding of the motor 63, 'Ille opposite contact EIS is connected 'oy a conductor 528 to the conductor 452 from which the circuit ccntinues through cont-acts 337 and 3B of the relay 438 and conductor ft to the other field winding of the m0ton83. The Contact 516 is connected .ag to the conductor 448 leading to conductor 3| which is connected tol one field winding of the speed motor H1.` The opposite contact 518'" is connected to the conductor 446 leading to the other eld winding of the same motor.

By virtue of the connections described above 4 vthe switch 300 will control the speed motor' ||`1 over conductors contacts 302, conductors 502, switch 52|, conductors 5|2 and the circuits through the arms and contacts of the quadrant switch |62 for wind angles in quadrants 1 or 3, in a manner similar to that in which the switch 300 controls the same motor through the switch |00 for a target angle in either of these quadrants.

Similarly, the switch 300 controls the course motor 83 over the same circuits and elements, as described above, when the wind angle lies in guadrants 2 or 4.

It will be understood that under these conditions of operation the motor 83 will drive through the shafts, gears and differential 58, the wind direction gear |31, as has been heretofore describedv in the operation of positioning the pin in train. Similarly the motor ||1 will drive through the shafts, gears and differential the wind velocity gear |42 as previously described.

The repositioning of the :pin by either of the motors will cause an actuation of the vertical slide |1|, the movement of which will be transmitted through pinion |16, shaft |11, and bevel gears |18 to the side |13 of differential H9. Regarding the center |19" as fixed the side |19"' will be turned and through shaft |8|', center I |21" and side |21" of differential |21, bevel gears 201, shaft 20S, gear 203, gear 231, side 298 and center 298" of differential 238 and shaft 299 the switch 358 will be operated to open the circuit of the motor which is repositioning the pin |40. Simultaneously with the repositioning of the pin, the wind velocity dial |59 and the wind angle ring |88 will be set in accordance with the corrected condition of the instrument in a manner similar to that previously described in connection with wind corrections insofar as training is concerned.

In the foregoing consideration of the rate control features of the instrument the correction of errors in the estimates of any of the quantities has been considered solely with respect to such quantities without considering their effect upon other quantities. For instance, in considering the effect of an error in the estimate of the speed of a target having a target angle in quadrant 4 no consideration has been given to the effect of the correction of target speed on the range rate or vertical angular rate.

By Way of illustration, one specific case will be considered to show the operation of the instrument under these conditions. For this purpose it will be assumed that the course of the target is along the line DE of quadrant 4 as shown in Fig. 5. In such a case the slot 9| of the target angle gear 88 will lie at an angle to both of the slides ||8 and H9 so that when the pin 93 is repositioned by the target speed motor ||1 as previously described in connection With the training rate control it will not only move the slide HB to de-energize the target speed motor which at this time is under the control of the switch 2|3, but it will also cause the actuation of the slide ||9 which through the differentials |21 and 298 will operate the switch 300 to control the target course motor 83 which is under the 3@ control: of. the switch` 300 under the conditions assumed. The course motor will through thedf'- ferential 10 turn. the target angle: lgears 85 and 95 to restore the slide |.8 to' its original position without' altering the position of slidef H8' as de'- termined by the new position of pin 93 to maintain the instrument in its corrected. conditionv in train; This may cause a reaction on the switch 213 to again drive the speed motorV but a condi-` tion of equilibrium willrlnally be reached. It is thus to be seen that when the component: controlling one rate is corrected the other compo,- nents remain at their previous value unless intentionally corrected.

In connection with this feature, at all times when the range rate correction switch 41'1 open and either or both of the trainers and pointers switches 338 and 11.53 respectively are closed, a circuit will be establishedv from the main 2|8 through switch 388' and/or switch 453., contact 388 and/or contact 854, conductors 39|,.and M5", andr M5, contacts 4181 and 419 of switch 81.1., conductor 430 and electro-magnet 88|A to the main 224. The electro-magnet 48| is fixed as shown in Fig. la so that when energized it attracts the armature 481 and locksthe shaft 488 andthe elements, such as the slide 354 controlled therefrom through switch 82 against accidental displacement. Actuation of switch 441 breaks the circuit of electro-magnet 48| to free the shaft 488 which is then clutched to shaft 485 by the armature 081 as previously described.

Reference has been made to the quadrant switches designated |00 and |82 and their shafts and Contact elements have been described. The

switches being similar the one designated |00 will be described in detail particularly in connection with Fig. 4 in which the actuating elements are shown more in detail and on an enlarged scale. As shown in Fig. la the switch |00 is actuated from the target angle gear 90 by the gear 91 which meshes with a gear 99 as well as with the target angle gear. The gear 95 is on a shift 52| which also carries a pinion 522, the latter being in mesh with a gear 523, which as shown in Fig. 4 is rotatably mounted on a stud 52d. The gear 523 is provided with a sleeve 525 on the lower end of which is a pinion 525, which in turn is in mesh with a. gear 521. The last named eear is loosely mounted on another stud 528 and is provided on its under side with a pair of pins 523 and 530. spaced below the gear 521 and also loosely mounted on the stud 528 is a mutilated gear 53| consisting of a disc provided with two depending gear teeth 532 and 533 between which there is a single tooth notch.

Coacting with the mutilated gear 53| is a pinion 535 having an upper portion 536 which is provided with four teeth and a lower portion 531 with four additional teeth. Its co-action with the mutilated gear 53| will be referred to hereinafter. The disc of the mutilated gear 53| is also provided with a pair of pins 538 and 539, which are spaced correspondingly to the pins 529 and 53e that are attached to the gear 521. The axes of upper pins 529 and 530 are coincident with the axes of the lower pins 538 and 539. Interposed between the upper gear 521 and the lower gear 53| is a C-shaped spring 550, which is Wide enough to overlap each of the upper pins 523 and 530Iand the corresponding lower pins 538 and 533, the ends of the spring 540 being curled about said pins. In being curled, a space is left between the main body of the spring and its 

